CAIRO — Sudan’s deposed leader, Omar Hassan al-Bashir, told investigators that he had received $90 million from Saudi Arabia, a Khartoum court heard on Monday during the opening of Mr. al-Bashir’s keenly anticipated trial on corruption charges.

A senior police officer testified that Mr. al-Bashir, who was ousted in April after months of street protests, had admitted to receiving part of the money from envoys sent by the Saudi crown prince, Mohammed bin Salman.

Mr. al-Bashir was confined to a cage in the two-hour hearing and spoke only to confirm his name and age, reporters at the trial said. His lawyer dismissed the accusations.

It was a dramatic start to a trial that has come to signify the sweeping changes underway in Sudan after Mr. al-Bashir’s 30 years in power, a period in which the country endured numerous internal revolts, became an international pariah and more recently suffered a crushing economic collapse that spurred the uprising against him.

Mr. al-Bashir, 75, has yet to face charges in the most serious accusations against him, including genocide and war crimes.

On Saturday, Sudan’s military and civilian leaders signed a power-sharing deal to run the country jointly for the next three years until elections can be held. A transitional government run by civilians, with a senior general in charge, is scheduled to assume power on Sept. 1.

The account on Monday of a large personal payment from Prince Mohammed also highlighted the enduring influence of one of the richest countries in the region on one of the poorest.

The Saudis and their ally, the United Arab Emirates, backed Mr. al-Bashir, who sent thousands of troops to support the Saudi-led war campaign in Yemen. But the Saudis and Emiratis quickly switched sides after Mr. al-Bashir was ousted, offering a $3 billion aid package to the military junta that had toppled him.

Mr. al-Bashir also faces a decade-old indictment at the International Criminal Court, which accuses him of genocide, war crimes and crimes against humanity in a military campaign in the western region of Darfur in which up to 300,000 people were killed. But Sudan’s military leaders, many of whom fought in Darfur under Mr. al-Bashir, have ruled out sending him to The Hague to face trial on those charges.

The trial being held in Khartoum, the Sudanese capital, focuses on corruption charges.

Not long ago, few Sudanese could have imagined seeing Mr. al-Bashir — for decades one of the great survivors among African autocrats — in a cage. Reporters in the courtroom on Monday said he waved his hand in greeting to supporters, who responded with cries of “God is great.”

Days after Mr. al-Bashir was ousted, police and military officials raided one of his residences and seized bundles of cash in various currencies that the military junta’s leader, Lt. Gen. Abdel Fattah al-Burhan, later valued at about $113 million.

Police Brig. Gen. Ahmed Ali Mohamed, a detective in the team investigating the deposed leader, testified that Mr. al-Bashir had admitted to receiving $25 million from Prince Mohamed and another $65 million in two payments from King Abdullah, the predecessor to the kingdom’s current monarch, Reuters reported.

Mr. al-Bashir faces charges of corruption, illegal possession of funds and money laundering, said Al-Rayah al-Sadig, a leader of the Sudanese Professionals Association, an alliance of doctors, lawyers, journalists, engineers and teachers that had a central role in the protest movement.

Sudan’s prosecutor general said in May that Mr. al-Bashir had been charged in the deaths of protesters in the uprising that eventually led to his ouster. That trial has not yet begun.